The Innate Immune System

Some of these chemical mediators are also responsible for some of the cardinal signs of inflammation. The pain, or ‘dolor’, associated with inflammation is due to this release of bradykinin and histamine from mast cells, which stimulate surrounding nerve endings. The vasodilation and increased vascular permeability they also produce are the causative factors of calor (meaning heat), rubor (meaning redness) and tumor (meaning swelling).